The present application is directed to electronic/electrical circuits or systems, and more particularly to connections for those known as flexible electronic/electrical circuits or systems.
Printed flexible hybrid electronic circuits or systems may require electrical interconnection to peripheral elements. For example, a printed sensor tag with wireless communication may need to connect to a printed sensing electrode on a separated substrate. Frequently, it is desired that these interconnections be detachable in order to replace peripheral elements or to facilitate low cost and simplified assembly, test, rework, and repair.
Unlike conventional printed circuit boards, mounting a connector on a flexible substrate is challenging due to low temperature requirements, such as known in the art.
FIGS. 1 and 2 illustrate solutions for electric flexible (flex) circuit or system interconnection. More particularly,
FIG. 1 depicts an arrangement 100 where two flexible circuits or systems 102, 104 are bonded together by an anisotropic conductive adhesive film (ACF) 106. The electric path between pads on the two substrates is established by embedded conductive particles after the application of heat and pressure. However, this type of connection is not considered detachable due to the intended permanent connection that is accomplished by ACF bonding.
Another solution for a flex-to-flex connection is by use of a zero insertion force (ZIF) connector 200, as shown in FIG. 2. With a ZIF socket, before a flex circuit is inserted, a lever on the socket is released, opening a gap so that the flex connection can be inserted with very little force. The lever is then engaged, allowing the contacts to close and grip the contact pads on the flexible circuit. ZIF sockets can be used for detachable connections. However, the ZIF fixture is commonly too rigid and bulky for applications requiring small form factors and desired or required flexibility.
Therefore it is considered useful to provide an electrical connection which permits interconnection between separate substrates, where at least one of the substrates is a flexible substrate. The connection should also be detachable and re-attachable for replacing different substrates carrying circuit elements.